Natalie Portman recently won a Golden Globe for best dramatic actress in the movie "Black Swan," and now has a new distinction. It's a number one comedy.

"No Strings Attached" opened in first place at North American theaters over the weekend. Preliminary estimates show the R-rated sex romp grossed $20.3 million. Natalie Portman and Ashton Kutcher star as friends with benefits.

Seth Rogen's action comedy "The Green Hornet" fell to second place in week two, with a predicted $18.1 million weekend. If that plays out, the total gross would be $63.4 million so far.

"The Dilemma" was in third place, with an estimated $9.7 million. Close behind with $9.2 million was "The King's Speech," which took the top prize Saturday night from the Producers Guild – an award that usually portends the Best Picture Oscar-winner.